A vapor delivery system and method is provided that includes a number of features. In one embodiment, a method comprises inserting a vapor delivery needle into tissue of a patient, activating a flow of vapor from a vapor generator through vapor delivery ports of the vapor delivery needle to cause condensed liquid to exit vapor delivery ports of the vapor delivery needle, generating vapor in the vapor generator, delivering a dose of vapor through the vapor delivery ports of the vapor delivery needle into the tissue, and after the dose of vapor is delivered, re-activating the flow of vapor from the vapor generator through the vapor delivery ports of the vapor delivery needle to prevent a vacuum from forming in the vapor delivery needle. Vapor therapy systems are also provided.